The present invention relates to laser mirrors and particularly to polarizing laser mirrors.
In order to achieve a well polarized laser, it is necessary to introduce within the laser cavity a device which exhibits a polarization selective loss. In low gain lasers, a surface pitched at the Brewster angle is usually used to achieve this loss. This surface can take the form of a tube window or perhaps a Littrow prism and mirror. Both of these approaches are relatively expensive since both require angular alignment and two laser quality optical surfaces.
It is a recognized technique in the long wavelength infrared regions to use gratings made of fine closely spaced metallic wires as polarizers. The dimensions of the wires and the spaces in between them are less than the infrared wavelengths. This technique is considerably expensive, however, due to the intricacies of the wire grating fabrication.